In article <20040129221538.J24747@xxxxxxxxxx> (at Thu, 29 Jan 2004 22:15:38
+0100), Jan Kasprzak <kas@xxxxxxxxxxxxxxxxxxx> says:
> while compiling the kernel (2.6.1) I have spotted the following warning:
>
> net/ipv6/ndisc.c: In function `ndisc_router_discovery':
> net/ipv6/ndisc.c:1113: warning: comparison is always true due to limited
> range of data type
:
> The corresponding lines are these:
>
> __u32 rtime = ntohl(ra_msg->retrans_timer);
>
>
> Here ---> if (rtime && rtime/1000 < (MAX_SCHEDULE_TIMEOUT/HZ)) {
> rtime = (rtime*HZ)/1000;
> if (rtime < HZ/10)
> rtime = HZ/10;
> in6_dev->nd_parms->retrans_time = rtime;
> }
:
> The MAX_SCHEDULE_TIMEOUT is #defined to LONG_MAX in include/linux/sched.h,
> which is 2^63-1 or so on AMD64. I propose the following fix:
:
+#define MAX_SCHEDULE_TIMEOUT_32 (MAX_SCHEDULE_TIMEOUT/HZ > (1U<<31) ? \
+ (1U<<31) : MAX_SCHEDULE_TIMEOUT/HZ)
Well,... ok for now.
For long term solution, I think it is better to store timing variables
in "unsinged long" type instead of int.
I think there's several places to be fixed.
We'll need proc_doulongvec_jiffies(), proc_doulongvec_userhz_jiffies().
--yoshfuji
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